面向任务的装备维修保障力量解聚方法

针对传统的装备维修保障力量派遣模糊、效率低下等问题,以受损装备为研究对象,以装备受损部位与维修专业之间的关系矩阵、修复受损装备时限为研究内容,以快速、精确派遣维修保障力量为研究目的,建立了面向任务的装备维修保障力量解聚模型。最后,重点分析并实例应用了装备维修保障力量解聚方法。     

完善公安边防部队干部选拔工作的几点思考

做好边防部队干部选拔工作在增强干部工作积极性、提高选拔公信度、发扬民主集中制等方面发挥着越来越重要的作用。边防部队需转变传统选人用人理念,大力培养优秀干部,提高干部选拔工作的科学性。破除唯票取人、唯分取人现象,坚持党管干部、德才兼备原则,促进边防部队干部队伍建设健康稳定发展。     

日军大屠杀前南京人口疏散检讨

抗日战争爆发后,国民政府鉴于战争的发展,计划疏散南京城市人口。但实际仅秘密疏散了公务人员眷属。上海沦陷前后,国民政府将南京公职人员作为重点对象进行疏散,对普通居民则发布了"战时妇孺迁移办法",而实际对其缺乏有效的疏散组织。究其原因,国民政府企图通过稳定首都南京社会秩序,向外界展示抗日的决心;所统制的交通工具,忙于军事输送及国府西迁,无暇顾及平民百姓的疏散。南京城陷后,大量市民滞留南京,日军大屠杀得以上演。嗣后,国民政府吸取了教训,在重点城市开展了人口疏散工作。     

二维水翼非定常空化流动动力特性的频谱分析

以雷诺平均模拟方程(RANS)为核心,采用RNGk-ε湍流模型与均相流空化模型,对二维水翼附近空化流场进行数值计算。在固定来流速度和空化数条件下,研究了空化形态随着水翼攻角的改变而变化的情况,并采用傅立叶变换(FFT)对水翼升力周期性信号进行了频谱分析。结果表明:水翼的空化形态是由空化数和攻角共同决定的,当空化数不变时,随着攻角的增大,空化程度更加趋于剧烈;在片状空化阶段,升力信号频率为低频信号,并随着攻角增大频率略有降低;在云状空化阶段,升力信号频率为中高频信号,随着攻角增大频率也略有降低;空化形态由片状空化阶段向云状空化阶段转化,在转化过程中存在一个过渡阶段,其升力信号频率在各个频段均具有一定的特征。     

船舶电力系统模拟训练评估算法

针对船舶电力模拟训练评估系统的设计与实现问题,分析了构建指标体系的方法。依据设计原则,设计了船舶电力模拟训练的评估指标体系。确定了各评估指标的算法,并根据层次分析法构建权重集,然后运用模糊评判理论建立了综合评估模型。选取某船电力系统模拟训练考核的实例,进行了考核和综合评估,结果表明:该方法科学,可操作性强。     

The loss‐averse newsvendor problem with supply options

In this article, we consider a loss‐averse newsvendor with stochastic demand. The newsvendor might procure options when demand is unknown, and decide how many options to execute only after demand is revealed. If the newsvendor reserves too many options, he would incur high reservation costs. Yet reserving too few could result in lost sales. So the newsvendor faces a trade‐off between reservation costs and losing sales. When there are multiple options available, the newsvendor has to consider how many units of each to reserve by studying the trade‐off between flexibility and costs. We show how the newsvendor's loss aversion behavior affects his ordering decision, and propose an efficient algorithm to compute his optimal solution in the general case with n options. We also present examples showing how the newsvendor's ordering strategy changes as loss aversion rises. © 2014 Wiley Periodicals, Inc. 62:46–59, 2015     

Auctions in the post‐change‐order period

A change order is frequently initiated by either the supplier or the buyer, especially when the contract is long‐term or when the contractual design is complex. In response to a change order, the buyer can enter a bargaining process to negotiate a new price. If the bargaining fails, she pays a cancellation fee (or penalty) and opens an auction. We call this process the sequential bargaining‐auction (BA). At the time of bargaining, the buyer is uncertain as to whether the bargained price is set to her advantage; indeed, she might, or might not, obtain a better price in the new auction. To overcome these difficulties, we propose a new change‐order‐handling mechanism by which the buyer has an option to change the contractual supplier after bargaining ends with a bargained price. We call this the option mechanism. By this mechanism, the privilege of selling products or services is transferred to a new supplier if the buyer exercises the option. To exercise the option, the buyer pays a prespecified cash payment, which we call the switch price, to the original supplier. If the option is not exercised, the bargained price remains in effect. When a switch price is proposed by the buyer, the supplier decides whether or not to accept it. If the supplier accepts it, the buyer opens an auction. The option is exercised when there is a winner in the auction. This article shows how, under the option mechanism, the optimal switch price and the optimal reserve price are determined. Compared to the sequential BA, both the buyer and the supplier benefit. Additionally, the option mechanism coordinates the supply chain consisting of the two parties. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 248–265, 2015     

基于粗糙集理论的军队代储应急物资品种选择

从军队对应急物资的需求特点及应急物资的特征属性出发,构建了军队代储应急物资品种选择的指标体系。在此基础上,通过部队调研和专家经验获得了一组军队代储应急物资品种选择的样本数据并形成了决策表,运用基于可辨识矩阵的属性频率约简算法对决策表进行属性约简,并对约简属性集进行属性值约简,提取出军队代储应急物资品种的选择规则。提取的规则简洁合理,能够为军队代储应急物资品种选择提供决策支持。     

加油车加油系统瞬变流数值分析

针对加油车加油系统管路结构,利用特征线法和有限差分格式,对2种典型加油工况建立数学模型。用C#语言编制程序,对2种工况的泵出口压力和系统流量进行数值分析,得到压力和流量随时间变化的关系曲线。计算结果表明:单枪加油工况出现压力波动时间较早,且压力波动幅值较大。此方法更好地反映了加油系统的动态变化过程,为加油车虚拟训练系统的开发提供了理论依据。     

地下工程非爆破开挖机械破碎法机理及应用

针对非爆破法开挖工序中的关键问题——导向孔布置方案优化,结合非爆破施工实作流程及工艺,利用波动理论探索了破碎锤冲击破岩机理。破碎锤通过钎杆冲击导向孔产生孔间贯穿裂缝进而破岩掘进,破碎锤冲击破岩的过程是岩石被拉坏的过程,孔间岩石中的切向应力是提高破岩效率的关键因素。基于岩石断裂力学理论,总结得出导向孔间裂缝产生、扩展、贯通的判据,并依托实际工程进行验算,理论计算结果与现场试验结果吻合良好,同时提出了导向孔布置优化方案的改进建议。